Fan belt -Peugeot 205 diesel?

Yes you can - the belt tension is changed by moving the alternator. As you stand looking into the engine bay, the alternator is down on the left near the front of the car - it has a wheel on it with a belt running round it, that is what is making the noise. The alternator has bolts through it's metal casing - loosen those bolts (have both socket and normal spanners to hand - take care not let the belt fall off), pull the alternator towards the front of the car as far as the belt will allow and hold it there, then re-tighten the nuts again.

The Serpent
March 2008